Free Astronomy Magazine March-April 2016

16 MARCH-APRIL 2016 SPACE CHRONICLES that this turbulent behaviour could be linked to the galaxy’s extreme luminosity. W2246-0526 blasts out as much light as rough- ly 350 trillion Suns. This startling brightness is powered by a disc of gas that is superheated as it spirals in on the supermassive black hole at the galaxy’s core. The light from the blazingly bright accretion disc in the centre of this Hot DOG does not escape directly, it is absorbed by a sur- rounding thick blanket of dust, which re-emits the energy as in- frared light. This powerful infra- The turbulent birth of a quasar by ESO Q uasars are distant galaxies with very active super- massive black holes at their centres that spew out powerful jets of particles and radiation. Most quasars shine brightly, but a tiny fraction of these energetic objects are of an unusual type known as Hot DOGs, or Hot, Dust-Obscured Gal- axies (only one of every 3000 quasars observed are classified as Hot DOGs), including the gal- axy WISE J224607.57-052635.0, the most luminous known galaxy in the Universe. This object was found by NASA’s Wide-field In- frared Survey Explorer (WISE) spacecraft and the rest of the name gives the precise location of the quasar on the sky. For the first time, a team of re- searchers led by Tanio Díaz-San- tos of the Universidad Diego Por- tales in Santiago, Chile, has used the unique capabilities of ALMA (in the detection of the faint, mil- limetre-wavelength light natu- rally emitted by atomic carbon) to peer inside W2246-0526 and trace the motion of ionised car- bon atoms between the galaxy’s stars. “Large amounts of this in- terstellar material were found in an extremely turbulent and dy- namic state, careening through- out the galaxy at around two million kilometres per hour,” ex- plains lead author Tanio Díaz- Santos. The astronomers believe